Ultraviolet light label monitoring system

ABSTRACT

A three-stage ultraviolet light label detection unit is provided for monitoring articles to detect and separate articles having luminescent, i.e., fluorescent or phosphorescent, imprints located thereon. The first detection stage uses ultraviolet light to sense the presence of luminescent imprints; the second control stage uses white light sensing to control the movement of articles passing thereby; the third reset stage also uses white light sensing to reset the control stage. Each stage acts through a logic circuit adapted to provide the desired detection and separation of luminescent from non-luminescent articles.

United States Patent Madalo et al. [4 1 May 9, 1972 154] ULTRAVIOLETLIGHT LABEL 3,348,049 l0/l967 Stacey.....-. ..209/111.5 x

MONITORING SYSTEM 3,512,637 5/1970 Littlefield ..209/74 [72] Inventors:Michael Madalo, Whitehouse Station, Primary Examiner kichard A schacherN.J.; William H. Marlow, Nanuet, N.Y.

[73] Assignee: American Cyanamld Company, Stamford,

Conn.

221 Filed: Mar. 12, 1970 [21] Appl. No.: 18,945

[52] U.S. Cl. ..209/1 11.7 [51] Int. Cl. ..B07c 5/342 [58] Field ofSearch ..209/74, 1 i 1.5, ML?

[56] References Cited UNITED STATES PATENTS 3,l42,383 7/1964 Boyer..209/11 L? X AMPLIFIER Attorney-Bryan, Parmelee, Johnson & Bollinger[57] ABSTRACT A three-stage ultraviolet light label detection unit isprovided for monitoring articles to detect and separate articles havingluminescent, i.e., fluorescent or phosphorescent, imprints locatedthereon. The first detection stage uses ultraviolet light to sense thepresence of luminescent imprints; the second control stage uses whitelight sensing to control the movement of articles passing thereby; thethird reset stage also uses white light sensing to reset the controlstage. Each stage acts through a logic circuit adapted to provide thedesired detection and separation of luminescent from non-luminescentarticles.

5 Claims, 3 Drawing Figures LOGIC 36 AMPLIFIER 4o [AMPLIFIER 42 1 l l l1 l l l l I 1 1 l l I l l I l l l 1 2s 32 I 30 1 ii RC. 501. 12. 1 14 25WHITE 1 29 uv LIGHT LIGHT 1o SOURCES N SOURCESI 1 L w- ..1...AM J 1 18 JJ H n/ FIRST STAG ssc'owo STAGE T(RPED5EJ1T L (DETECTION (CONTROL)ULTRAVIOLET LIGHT LABEL MONITORING SYSTEM SUMMARY OF THE INVENTION Ourlabel monitoring system can most readily be described as a three-stagesystem. EAch stage performs a systematic function cooperating with theother two stages. The first is a detection stage; the second, a controlstage; and, the third, a reset stage. The detection stage has a sourceof ultraviolet light arranged to illuminate an article passing by it.The article may be bottle, box, carton, or other container normallyhaving a label on it.

The label contains a luminescent mark or imprint, so that, when thearticle bearing the label passes into the ultraviolet light zone and isilluminated, the luminescent material, if present, will fluoresce orphosphoresce, emitting radiation, usually of visible light. The emittedlight activates a photocell included in the detection stage which inturn energizes a logic circuit electrically connected to the controlstage.

The control stage is normally set to reject all articles passing throughit, using a source of white light and a photocell detector to determinethe presence of the articles. However, if the photocell in the detectionstage senses luminescent material, the control stage is directed by thelogic circuit not to reject the article, and so it is permitted to pass.

The reset stage includes another source of white light and anotherphotocell to detect passing articles. This stage resets the controlstage to its normal operating, i.e., automatic reject, state when thereset stage photocell is activated.

The monitoring system thus provides a three-stage detection andseparation unit, controlled by the presence or absence of luminescentmaterial on a label, for detecting and separating articles.

For a better understanding of the features and advantages of the presentinvention, the detailed description should be read in conjunction withthe following figures.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view generallyshowing the arrangement of the articles and sequence of operation of themonitor- DETAILED DESCRIPTION STRUCTURE This invention discloses a labelmonitoring system using a pluralityof sequentially arranged stages, eachstage performing a specific function in the detection and separation oflabelled from non-labelled articles. Each label contains a luminescentmaterial capable of activating a photocell when the luminescent materialis exposed to ultraviolet light. The first stage inspects passingarticles to detect the presence of luminescent imprints. The secondstage, having a white light detector, controls the path of an articlepassing thereby. (It is nonnally set to reject the article unless asignal is received from the first stage). The third stage, alsosensitive to white light, resets the control stage to its normal rejectstate.

The preferred form of our invention is shown in FIGS. 1, 2, and 3. FIGS.1 and 2 show the structural layout, and FIG. 3 shows the logiccircuitry.

Turning first to FIGS. 1 and 2, our system includes means for conveyingan article, the three stages mentioned above, the logic controlcircuitry, and article rejection means.

For purposes of illustration,.we have shown bottles having labels 12 onthem. Also shown is one bottle 11 without a label. The bottles arecarried on a conveyor belt 18 which is shown moving to the right in thefigures.

Each label should have a mark 14 of fluorescent material on it. It isthis mark 14 which is detected in our system, thereby detecting thepresence or absence of a label.

Positioned adjacent to belt 18 and preferably to one side of it, aredetection, control and reset stages, in that order, identified bynumerals 20, 24 and 28, respectively.

The first (detection) stage 20 includes source of ultraviolet light 21and photocell detector 22. The second (control) stage 24 includes asource of visible light 25 and a photocell detector 26; and alsoincludes a rejector 27. The third (reset) stage includes a source ofvisible light 29 and photocell detector 30.

The rejector 27 in the second stage may be of any desired type. A rejectplunger, actuated by a solenoid 32, adjacent belt 18 and positioned topush bottles transversely off belt 18, is satisfactory. When actuated,the plunger pushes the bottle 10 onto a reject station 34, as shown bythe arrows in FIG. 1.

The three stages and rejector are interconnected through logic circuit36 and, if necessary, amplifiers 38, 40 and 42. That is, the output offirst stage photocell 22 passes through amplifier 38 to logic circuit36; and that of the third stage photocell 30, through amplifier 42, tologic circuit 36. The output from logic circuit 36 goes to solenoid 32to control the reject plunger.

In our preferred form, logic circuit 36 is adapted to reject everybottle passing through control stage 24, unless it receives a signalfrom detection stage 20 indicating that luminescent material is present.Normally, logic circuit 36 actuates solenoid 32 each time a bottle 10 isdetected in the second stage. Thus, the system is fail-safe. If,however, a signal is received from detection stage 20, indicating thepresence of luminescent material, control stage 24 is deactivated,preventing rejection. When that bottle passes photocell 30 of the thirdstage, logic circuit 36 then reactivates, i.e., resets, control stage24.

It should be realized that other types of logic programs could be used,if desired, in our three-stage system. For example, the second stagecould be set to reject" when a signal is received indicating thepresence of marking on the label. In such a case, the reset stage 28would be positioned over the reject station 34.

A form of logic circuit which may be used is shown in FIG. 3. Inessence, this circuit is designed to have solenoid 32 actu ated eachtime a bottle reaches the second stage, thus rejecting the bottle. Thisactuation is accomplished by having the second stage photocell 26 closethe circuit to solenoid 32 each time it detects the presence of abottle. If, however, a luminescent label on the bottle has beenpreviously detected by photocell 22 at the first stage, solenoid 32 isdeactivated and cannot reject.

The circuit itself includes solenoid coil 32 and resistor 33 in serieswith normally-open relay 46 controlled by second-stage photocell 26 andnormallyclosed relay 48 controlled by first stage photocell 22. The coiland two relays are across a power supply 44, so solenoid 32 will operatewhen relays 46 and 48 are closed.

Closure of normallyopen relay 46 occurs when its photocell 26 detects abottle. Thus, every bottle entering the second stage is rejected unlesssolenoid 32 is deactivated.

Deactivation occurs by short-circuiting solenoid 32. Relay coil 50,having normally-open contacts 54, is in series across the power supplywith normally-open relay contacts 56 controlled by first-stage photocell22. Thus, when a bottle with a luminescent label is detected byphotocell 22, the circuit of contacts 56 and coil 50 is closed, shortingout solenoid 32 (since they are in parallel with it across the powersupply.)

Energization of coil 50 also closes its associated relay contacts 54.Contacts 54 are in series with coil 50 and normallyclosed relay contacts58 controlled by third stage photocell 30. This series circuit is inparallel with that of coil 50 and contacts 56, so solenoid 32 remainsshort-circuited even after the bottle leaves the first stage andcontacts 56 again open.

Thus it can be seen that solenoid 32 will be deactivated, and so notreject a bottle entering the second stage, if a signal is received fromthe first stage.

Under these latter circumstances, however, the logic circuit must bereset to "reject" before the next bottle reaches the second stage. Thishappens because the then "passed" bottle moves to the third stage and isdetected by photocell 30. This opens relay contact 58 and deenergizescoil 50. Solenoid 32 is thereby reset" since it is no longer shortedout. The cycle may then be repeated.

In summary, solenoid 32 rejects every bottle passing under photocell 26unless prevented. It is prevented whenever photocell 22 detects aluminescent sample and so, through contact 56 and coil 50 shorts out anddeactivates solenoid 32. Solenoid 32 will thereafter remain deactivateduntil a bottle, not rejected goes under photocell 30.

OPERATION The operation of our label monitoring system is as follows:

Normally, as bottle proceeds along the conveyor belt 18, the secondstage photocell 26 will detect its presence, closing relay 46. Thisaction closes the circuit to the reject solenoid 32, actuating thereject plunger 27 to push the bottle 10 off the belt 18 onto the rejectstation 34. Thus, the logic circuit is programmed to reject every bottle10 unless prevented in some manner.

The prevention occurs through actuation of photocell 22 in the firststage 20 whenever the presence of luminescent material is detected onthe bottle 10. Such actuation of the photocell 22 closes thenormally-open relay 56 thereby shortcircuiting the reject solenoid 32,de-activating it.

Further, the activation of the relay coil 50 closes normallyopencontacts 54. This action of the relay coil 50 holds the circuit throughthe relay coil 50 closed even after the bottle 10 passes the photocelldetector 22 opening relay 56. Thus, the action of the relay coil 50prevents the rejection of a bottle 10 until it is deactivated.

Deactivation occurs when an accepted bottle 10 is detected by photocell30. When such detection occurs the normallyclosed relay 58 is opened,deactivating the relay coil 50 and returning the circuit to its originalsetting as described above and as shown in FIG. 3.

It should be understood that the various arrangements of the stages ormodification in the construction thereof may be made by one skilled inthe art without departing from the spirit or scope of the invention asset forth in the specification and claims.

We claim:

1. Apparatus for sorting articles in accordance with the presence orabsence of luminescent material thereon, said ap paratus including adetection stage, a control stage, and a reset stage, a detector in eachsaid stage, said detection stage detector being adapted to detectradiations from activated luminescent material, a logic circuitinterconnecting said detectors to receive information therefrom, aconveyor to carry said articles sequentially through said stages, arejector in said control stage controlled by said logic circuit, saidlogic circuit activating and deactivating said rejector in accordancewith whether or not said detection stage detector finds luminescentmaterial present on said articles as they pass through said detectionstage.

2. Apparatus as set forth in claim 1, in which said logic circuit isadapted to actuate said rejector each time one of said articles passesthrough said control stage unless said detection stage detector hasfound luminescent material present on said article when it passedthrough said detection stage.

3. Apparatus as set forth in claim 2, in which said logic circuit isreset to cause said rejector to thereafter reject each time one of saidarticles is detected by said reset stage detector.

4. Apparatus for sorting articles including a detection stage includinga detector therein sensitive to radiations from activated luminescentmaterial, a following control stage including a visible light detectorand a rejector therein, and a following reset stage including a visiblelight detector, said detectors and said rejector being interconnectedthrough a logic circuit,

said logic circuit beinig programmed to actuate said rejector to re ecteach said artic e as it passes through said control stage and isdetected by said control stage detector unless said detection stagedetector has found luminescent material on said article, said resetstage detector resetting said logic circuit to again cause rejection ofarticles as soon as a non-rejected article leaves said control stage andis detected by said reset stage detector.

5. Apparatus for sorting articles as set forth in claim 4, in which saidlogic circuit controls said rejector by deactivating same each time saiddetection stage detector finds the presence of said luminescent materialand by reactivating same every time said reset stage detector detectsthe presence of one of said articles.

* t a: a:

1. Apparatus for sorting articles in accordance with the presence orabsence of luminescent material thereon, said apparatus including adetection stage, a control stage, and a reset stage, a detector in eachsaid stage, said detection stage detector being adapted to detectradiations from activated luminescent material, a logic circuitinterconnecting said detectors to receive information therefrom, aconveyor to carry said articles sequentially through said stages, arejector in said cOntrol stage controlled by said logic circuit, saidlogic circuit activating and deactivating said rejector in accordancewith whether or not said detection stage detector finds luminescentmaterial present on said articles as they pass through said detectionstage.
 2. Apparatus as set forth in claim 1, in which said logic circuitis adapted to actuate said rejector each time one of said articlespasses through said control stage unless said detection stage detectorhas found luminescent material present on said article when it passedthrough said detection stage.
 3. Apparatus as set forth in claim 2, inwhich said logic circuit is reset to cause said rejector to thereafterreject each time one of said articles is detected by said reset stagedetector.
 4. Apparatus for sorting articles including a detection stageincluding a detector therein sensitive to radiations from activatedluminescent material, a following control stage including a visiblelight detector and a rejector therein, and a following reset stageincluding a visible light detector, said detectors and said rejectorbeing interconnected through a logic circuit, said logic circuit beingprogrammed to actuate said rejector to reject each said article as itpasses through said control stage and is detected by said control stagedetector unless said detection stage detector has found luminescentmaterial on said article, said reset stage detector resetting said logiccircuit to again cause rejection of articles as soon as a non-rejectedarticle leaves said control stage and is detected by said reset stagedetector.
 5. Apparatus for sorting articles as set forth in claim 4, inwhich said logic circuit controls said rejector by deactivating sameeach time said detection stage detector finds the presence of saidluminescent material and by reactivating same every time said resetstage detector detects the presence of one of said articles.